Bootstrap 4 collapse has delay

Question

I'm creating offcanvas navigation menu on mobile view and I have encountered a problem where there is like 0.3s delay before adding class .show.

I tried adding custom class .active via jquery but results are the same - even tho that class is added without delay, transition on this class is still delayed.

.collapse.active{
  transform: translateX(0%);
}

That's most likely caused by adding and calculating inline style height that I don't really need as i alyways want nav to be 100vh. Is there a way to cut or speed up the calculating part?

Tried adding this code but doesn't help at all.

.collapsing {
-webkit-transition: all 0s ease-out;
-o-transition: all 0s ease-out;
transition: all 0s ease-out;
height:0 !important;
display: none;
}

Bootply link (with delay): https://www.bootply.com/9dFOT7Q2Ct

I did same thing on codepen and there it works just fine - It doesnt even add inline style to #navbarNav so maybe a jquery issue (I'm using recommended jquery-3.2.1)

Codepen link (without delay for some reason): https://codepen.io/janheder/pen/rGLJLb

Answer 1

You might be experiencing a delay because bootstrap adds a collapsing class before show to the navbar to offer more control over animation.

If you are looking for a smooth transition I believe this might help: https://www.bootply.com/rPqvbgcCVj

body {
  overflow-x: hidden;
  -webkit-transition: margin .3s ease;
  -moz-transition: margin .3s ease;
  -o-transition: margin .3s ease;
  transition: margin .3s ease;
  width: 100%;
  margin: 0;
  font-family: -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    "Helvetica Neue",
    Arial,
    sans-serif;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.5;
  color: #212529;
  background-color: #fff;
}

.navbar-light .navbar-nav .nav-link {
  padding-right: 1.5rem;
  padding-left: 1.5rem;
  position: relative;
}

.navbar .menu-item.menu-item-has-children > .nav-link:after {
  content: "";
  width: 0;
  height: 0;
  border-style: solid;
  position: absolute;
  right: 0;
  top: 50%;
  -ms-transform: translateY(-50%);
  -webkit-transform: translateY(-50%);
  transform: translateY(-50%);
  border-width: 4px 4px 0px 4px;
  border-color: #007bff transparent transparent transparent;
}
/* Added the following code and removed previous code */
.collapsing {
  transform: translateX(0%);
}

@media (max-width: 991px) {
  body.active {
    overflow: hidden;
    height: 100%;
    width: 100%;
    margin-left: -280px;
  }
  .collapse.active {
    transform: translateX(0%);
  }

  .navbar-collapse {
    position: fixed;
    right: 0px;
    top: 0px;
    display: block;
    transform: translateX(100%);
    height: 100vh;
    width: 280px;
    transition: transform .3s ease;
    overflow-y: scroll;
    background: #fff;
  }
  /* Added the following code */
  .active.collapsing {
    transform: translateX(0%);
  }


  .navbar .menu-item.menu-item-has-children > .nav-link:after {
    right: 1.5rem;
  }
}